17Î HSD type 5 INHIBITOR.

It is intended to provide a novel and excellent method of treating and/or preventing prostate cancer, prostate enlargement, acne, seborrhea, hypertrichosis, calvities, alopecia, sexual precocity, adrenal hypertrophy, multilocular ovary syndrome, breast cancer, lung cancer, endometriosis, leiomyoma and so on based on an effect of selectively inhibiting 17Î HSD type 5. It is found out that an N-sulfonylindole derivative, in which a carbon atom in the indole group is substituted by a carboxy group, a carboxy-substituted lower alkyl group or a carboxy-substituted lower alkenyl group, has a potent activity of selectively inhibiting 17Î HSD type 5 and is usable as a remedy and/or a preventive for diseases, in which 17Î HSD type 5 participates, such as prostate enlargement and prostate cancer without showing any side effect caused by a decrease in testosterone.